Filter



FIG. 1 is a perspective view from above of a filter showing my new design;

FIG. 2 is a right side elevational view thereof, with the left side elevational view being a mirror image thereof;

FIG. 3 is a front elevational view thereof, with a rear elevational view being a mirror image thereof;

FIG. 4 is a top plan view thereof; and,

FIG. 5 is a bottom plan view thereof. 

The ornamental design for a filter, as shown and described. 